A trash-talker may intimidate. A jarring hitter can inspire dread. A ball-hawk may cause second thoughts of throwing in his direction. Yet the scariest defensive players typically are those that offenses must account for on every play.

That's why North Carolina junior defensive end Robert Quinn, who is abnormally humble and quiet for a dominant defender, ranks among the scariest defensive players in the nation.

"I guess you don't have to be a big trash-talker to scare opponents," said Quinn, who had 11 sacks and 12 quarterback hurries last season. "If they're constantly chipping you, they're showing you respect."

New USF coach Skip Holtz, who coached East Carolina last season, certainly respects Quinn. East Carolina allowed 14 sacks last season, and Quinn had two of them.

"He's definitely a guy that you have to know where he is," Holtz said. "You have got to have a plan in case your tackle can't block him because that's a distinct possibility."

Hey, ease up on offensive tackles. Seriously, if a brain tumor can't stop Quinn, what chance does a tackle have?

When Quinn was a 17-year-old senior at Charleston (S.C.) Fort Dorchester, he was diagnosed with a benign brain tumor. The tumor was so deeply imbedded in his brain that doctors felt it was inoperable and instead drilled underneath it to drain spinal fluid and release pressure in October 2007.

"I just tried to keep things in reality," Quinn said of that ordeal. "There were two possibilities - either I could play football or I couldn't play football. I always tried to stay on the upside. People around me were more worried than I was.

"My mom was real, real worried. But if anybody came to see me in the hospital I told them, 'I'm all right; don't worry. I'll be back to a normal life.' "

A few months after the surgery, he won the state high school wrestling championship. By the next September, he was in the North Carolina starting lineup. Last season, he earned first-team All-ACC recognition after leading the conference with 19 tackles for loss.

That's enough to inflate most egos to enormous proportions. But while Quinn's performance has soared, his feet remain firmly planted.

"I'm really just a humble guy," he said. "That's how I was raised. And what I've been through with my brain tumor problems, I know anything can be taken away from you. I don't take my talent for granted, but I don't try to brag or anything."

That's OK. UNC coaches will do that for him.

"Robert has all the ability to be a special player," Tar Heels coach Butch Davis said. "He's such a humble young man who has persevered through so much in his life to be the kind of great human being that he is.

"He plays with tremendous tenacity, is a strong player and has a chance to be one of the best defensive linemen in the country."

Count Holtz among those convinced.

"I remember him as a recruit coming out. He had the brain tumor and he came back from that," Holtz said. "He's athletic, quick, fast, big … use any word you want to put. He's just athletic and a great player. I know he had a lot of sacks for them.

"You have to watch out for the speed he has off the edge and his athleticism. And as big as he is, he can overpower you. You've got to chip him or have a tight end help out."

Apparently, everybody has figured that out.

"In the Miami and Pittsburgh games, they let me know they were aware of where I was," Quinn said. "In the Miami game, I got chipped every play but one. Against Pittsburgh, it seems like they constantly cracked back on me."

That's the price of respect. Still, despite paying that price, Quinn - with 13 career sacks and two remaining years of eligibility - could threaten Greg Ellis' school record of 32.5 career sacks.

That is, if he stays at North Carolina for four years like several of his teammates, who could have entered this year's draft, but opted to stay in school for the 2010 season. Tackle Marvin Austin and linebacker Quan Sturdivant likely would have been taken in the first two or three rounds.

In all, the Tar Heels return nine starters from last season's defense, which allowed just four opponents to score more than 20 points.

"We know the potential we have," Quinn said. "The newspaper can say one thing, but on-field performance says another. We know we can be great. We just have to go out on the field and perform great."

Quinn certainly has.

THE 12 SCARIEST DEFENDERS
(listed alphabetically)

Oklahoma E Jeremy BealPARTICULARS: 6-3/261, Sr.; Carrollton (Texas) Creekview
BUZZ: An explosive pass rusher off the edge, Beal also has the speed to run down backs on sweeps to the opposite side. He has 20.5 career sacks, including 11 last season. He's the first OU player in history to have two three-sack games in the same season. He also had 19 tackles for losses and 70 total tackles.

Arizona State LB Vontaze BurfictPARTICULARS: 6-3/245, Soph.; Corona (Calif.) Centennial
BUZZ: Great middle linebackers typically have nasty demeanors. Burfict is another example. OK, so he gets a few late-hit penalties and he punched Arizona's long-snapper at the end of that game last season. He needs to channel that all aggression to the field and get even better. He had 69 tackles and two sacks to make everybody's freshman All-America teams in '09. He also made some big hits that have showed up on the Internet.

Nebraska T Jared CrickPARTICULARS: 6-6/285, Jr.; Cozad (Neb.) High
BUZZ: Crick, a converted defensive end, relied primarily on quickness to post 10 sacks and 14 quarterback pressures last season. He'll incorporate brute strength into his game more this season. Could he take over for former teammate Ndamukong Suh and be the best defensive tackle in college football?

Ohio State E Cameron HeywardPARTICULARS: 6-5/288, Sr.; Suwanee (Ga.) Peachtree Ridge
BUZZ: Don't make Heyward mad. Penn State QB Daryll Clark did last year - jabbing Heyward in the face after scoring a touchdown. Heyward - the son of former NFL RB Craig "Ironhead" Heyward - channeled his anger into an 11-tackle, two-sack performance in a dominating 24-7 Buckeyes win. Heyward, who finished with 46 tackles and 6.5 sacks last season, has the quickness to be an effective pass rusher and the strength to handle the run. If the Buckeyes can keep him mad all season, there's no limit to what he could accomplish.

Alabama LB Dont'a HightowerPARTICULARS: 6-4/250, Jr.; Lewisburg (Tenn.) Marshall Co.
BUZZ: Word out of Tuscaloosa last season was that Hightower was the Crimson Tide's best linebacker, even better than All-America Rolando McClain. That was before he suffered a knee injury. He's strong, fast and relentless. Here's betting he comes back strong and shows why some compared him favorably to McClain.

Michigan State LB Greg JonesPARTICULARS: 6-1/228, Sr.; Cincinnati Moeller
BUZZ: A playmaker at middle linebacker, Jones has great range and packs a powerful pop at the point of contact. Last season, he earned All-America honors while leading the Big Ten with 154 tackles, including a team-high 13.5 for losses. His tackle total was the third-highest in the nation. He also had nine sacks.

Purdue E Ryan KerriganPARTICULARS: 6-4/263, Sr.; Muncie (Ind.) Muncie Central
BUZZ: He's bulldog relentless - ask Ohio State. Kerrigan played a key role in the Boilermakers' upset of the Buckeyes with nine tackles, three sacks, two forced fumbles and a fumble recovery. Kerrigan led the nation with seven forced fumbles, led the Big Ten with 13 sacks and was fourth in the Big Ten with 18.5 tackles for loss.

Clemson SS DeAndre McDanielPARTICULARS: 6-1/210, Sr.; Tallahassee (Fla.) Godby
BUZZ: Quarterbacks should think twice about throwing over the middle with McDaniel looming there. Last season, he snatched eight interceptions, which he returned for 182 yards and a touchdown. If that's not enough to make opponent leery, consider that he's also a punishing tackler who made 102 stops in '09.

Pittsburgh DE Greg RomeusPARTICULARS: 6-6/270, Sr.; Coral Springs (Fla.) Coral Glades
BUZZ: Romeus is an imposing figure flying in off the edge. Even more frightening is that he keeps getting better. He arrived at Pitt in 2006 as a skinny 220-pounder who'd played just one year of high school football. Last season, he was the co-Big East defensive player of the year after notching 43 tackles, eight sacks, five pass breakups, 11 quarterback hurries and three forced fumbles. He should be even better in 2010.

North Carolina E Robert QuinnPARTICULARS: 6-5/270, Jr.; Charleston (S.C.) Fort Dorchester
BUZZ: He isn't talkative and doesn't try to draw attention to himself. But you can bet opposing offenses always are scheming to contain him. Last season, he had 11 sacks, 12 quarterback pressures and six forced fumbles. He should be a focal point of one of the nation's best defenses this season.

Olin Buchanan is the senior college football writer for Rivals.com. He can be reached at olin@rivals.com.